Telephone-exchange system.



Patented Dec. {1, 1917.

6 SHEETS-SHEET llm en for A/ben E. LL/Ho/e/Z A. E. L UNDELL. TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED DEC-211MB.

A. E. LUNDELL.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED DEC-2.1916.

Patented Dec. 4,1917.

6 SHEETS-SHEET 2- ill) Fig. 2.

' //7 var/for:

A/hen E. L nda/I.

I 'Affjv,

A. E. LUNDELL.

TELEPHONE EXCHANGE SYSTEM. APPLICATION FILED 050.2. I9I6.

39,1 11 Patented Dec. 4, 191?.

6 SHEETSSHEET 3- A E. LUNDELL.

TELEPHONE EXCHANGE SYSTEM. APPLICATION FILED DEC. 2. 1916.

LQQJ. $9 Patented Dec. 4,1917.

6 $HEETSSHEET 4- /n yen for:

A. E. LUNDELL- TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED DEC- 2. 1916.

' I Patented Dec. 4,1917.

6 SHEETSSHEET 5 M van f0 P: A/hen E. Luna/ell.

A. E. LUNDELL.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED oscnz. l9l6- 1,249,146., Patented Dec. 4,1917.

6 SHEETS-SHEET 6- ALBEN E. LUNDELL, OF NEW YORK, N. 1., ASSIGNOR To WESTERN ELECTRIC COMPANY, INCORPORATED, on NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELErHoN XoEANeE sYsTEM.

Specification of Letters Patent.

Patented Dec. 4, 1917..

l Application filed. December 2, 1916. Serial No. 134,559.

To all whom it may concern:

Be 1t known that I, ALBEN E. LUNDELL, a citizen of the United States, residing at New York, in the county of Bronx and-State of New York, have invented certain new and useful Improvements in Telephone EX- cha-nge Systems, of which the following is a ployed, and in whichpartyline ringing is panel type selector or connector. switch,

accomplished through a single set of terminals per line.

The object of this invention is the improvement in the circuits and control of se 'lective s1 'nalm a aratus of art l1nes 1n n p p a an automatic telephone system.

A feature of th s inventlon isthe provision of a doublebrush trlpplng zone in a whereby the same set of brushes may be selected in one of two ways -the choice of one or the other ofthese'two ways resulting in a circuit change which defines the character of the ringing current to be transmitted to the called party line. i

In a system embodying this invention, an operator sets up on a register the number of the called line and a letter designating the party Wanted on that line. The re isteris so arranged that'oncalls to direct l1nes and to the negative station of the ring side of the party line, the regularimpulses are sent out in the well-known manner. On calls to other stations of party lines, an additional set of five impulses is sent out with the incoming brush or with the final brush impulses, or with both, causing thereby the movement of the brush rod of the incoming or the final selector to a second brush tripping zone. By means of additional trip fingers of the trip rod, the same set of brushes is tripped as would hat e been the case had the call been for a direct line. The additional movement causes a change in the conditions for ringing, so that any of the four stations can be rung.

' Heretofore, systems have been devised in which such selection has been accomplished, such for instance as that disclosed inthe application of'Reeves and Lundell, Serial No. 73,223, filed January 20, 1916. The present invention, however, is an improvement in many respects, the ch f of which is the use of the ordinary number of counting relays, instead of double the number as in the case cited.

An additional feature of this invention is the provision of means for a more reliable con'trolof registers and keys. In its broadest aspects this improvement consists in a tiple of switches each controlled by a digit register. The arrangement of the switches is such that the actuation of any single one will result in the energization of one relay only, while the other relay will remain deenergized until every switch has been actuated'. Th e final operation of the latter relay is made to signal the completion of the setting ofthe registers and to initiate the further operationof the apparatus connected therewith.

"The drawin s'are arranged so that when Figure 2 is placed to the right of Fig. 1, Fig. 3 to the right of Fig. 2, Fig. 4 to the right of Fig. 3, Fig. 5 below Fig. 1 and Fig. 6 to the right of Fig. 5, a complete telephone system is diagrammatically represented. Fig. lrepresents in detail a calling subscribers line, an operators position, a cord circuit and a first selector switch. Fig. 5

represents a cord finder switch and a set of counting relays. Fig. 6 represents a register, which through the cord finder swltch and counting relays, is instrumental in extending a call through the first selector. Fig. 2 represents the extension of a call from the first selector to a connectingcircuit in a distant exchange and a second selector at that point. Fig. 3 represents the extension of the call from the second selector to a final selector or connector switch. Fig. 4: represents the extension of the line from the connector switch to the called party line, four stations being shown on this line.

In a number of the drawings,sequence switches such as 100 in Fig. l are shown. These switches are substantially of the construction disclosed in Patent No. 1,127,808. Each is provided with a motor magnet which, when energized, forces a rotatably mounted disk into contact with a constantly rotating disk, and thereby rotates a spindle on which are mounted a number of electrical contactors. These contactors, such for instance as 101 in Fig. 1, are arranged to close a circuit in the positions indicated by the numerals adjacent thereto. Each switch is also provided with a control contactor, such as A which is so arranged that an energizing circuit is completed through the motor magnet in all positions except those indicated by the numerals adjacent thereto.

In Figs. 2 and 3 brush tripping mechanism is represented which is substantially similar in construction to that disclosed in Patent No. 1,177,044. Each selector switch is provided with a set of multiple brushes, and mechanism is provided whereby any desired set of brushes may be put in operation.

Referring now especially to Fig. 1, we may assume a call to be initiated by the subscriber at substation S. The action of this subscriber in removing the receiver from its switch hook results in the establishment of a circuit from ground, the right-hand winding ot'wline relay LR, the inner armature and contact of cut-off relay CO, through one limb of the subscribers line to and through thea'pparatus of the substation S, through the other limb orthe subscribers line, contact and outer armature or eut-oflf relay CO,

the left-hand winding of line relay LR to battery and thence to ground. This results inthe energization of line relay LR, whereupon a circuit is established from ground, to contact and armature of. line relay LR, the line lamp LL to battery and thence to ground. a a v a,

The operator whose circuit is designated by the numeral 0, upon observing the lighting of lamp LL, inserts the plug P in the jack J, which is associated with the line lamp LL. This results in the establishment of a'circuit from. ground, battery, thewinding or cut-ofli' relay CO, the sleeve of the ack J, sleeve of the plug 1, winding of relay 150 to ground. The consequent energizatlonof cut-off relay CO removes the line relay Lltand its associated line lamp from the control of the subscribers line. At the same tlme the energizatlon of relay 150 completes a circuit from ground, the-armature and alternate contact of relay 150,

sequence switch contact 101 (position 1) the motor magnet of sequence switch 100 to battery and thence to ground. Sequence switch 100 moves under control of its contact A into its second position.

As sequence switch 100 moves its contactors into the second position, a circuit is established between. ground. sequence switch contact 102 (position 2),.sequence switch contact 501 (position 1), to the motor mag- I net of sequence switch 500, battery and thence to ground. Sequence switch 500,

4 common conductor under control of its contact A moves its contactors into the second position.

Themovement of the 'contacto'rs of sequence switch 500 into the second position results in -the establishment or a circuit from ground, battery, the winding of magnet 550, sequence switch contact 502 (position. 2) normal contact and right-hand armature of relay 551 and thence to ground. Magnet 550, upon attracting, its armature, forces the drivingribbon' DR against the constantly rotating roller 552, whereby the brush carriage B is elevated. Thebrushes Z2 Z2 b 22* and 5 move over and make contact with the associated terminals 3 t 15 ,5 and .1 hen the brush 5 encounters the terminal]? connected with the cord circ-uit which the operator 0 has chosen for the extension ot the call initiated by the subscriber Spa circuitfjis established between ground, sequence switch contact 102 (position 2), terminal t brush sequence switch contact 503 (position 2), winding Belay 551 is energized in. this circuit and attracts its armatures, whereby aycircuit is established between ground, the r1ght-hand armature and alternate contact otrelay 551, sequence sw tch contact 501 (posltlon 2) ,the w mdmg of motor magnet of sequence switch 500, to battery and .thenceto ground.1 Sequence switch 500 moves 1ts contactors,

under control of its contact 151 into the third position, thereby opening the energizing circuitof magnet 550at sequence switch contact 502, and allowing the brushes 5 to If to ,cometo rest on the terminals 2?} to f of the selected cord circuit.

An alternate circuit for the energization of relay 551 is completed. upon the attract1on oi 1ts .armatures between ground, battery, the winding of relay 551, sequence switch contact (positions 2 to 11), contact and left-hand armature of relay 551, 1

brush b terminal t sequence switch con- .tact 102- (positions 2 to 11) and thence to .oi 'relay 551 to battery and thence to ground. a

telephone of the party wanted is 869T5-J,-

the digit 8 representing the oflice in'which the calledpartys line terminates, the number 6975 representin g his line'and the letter J representing his station. The operator 'thereu1: on presses keys K K K K K and KF." Then the last key, that is, K has been pressed, av circult is established from ground, light-hand contactgkey K", to a 2572, 673, 674., 675 and 676, the normal @011- 070, to which are multi- .pled the right-hand armatures of relays 671,

taots of these ,armatures extending the. conneotion in each case, from thecommonconductor 670 to the motor magnets of sequence switches 610, 620, 630, 6 10, 650 and 660 respectively, and from there on in each case to battery and thence to ground. 7

Each one of these sequence switches will thereupon move from" the position in which it has now been found to a position deteriined by the keys K to K respectively. In the case of sequenceswitch 610, the movement will continue until the eighth position is reached, uponwhich a circuit is established from ground, contact of key K sequence switch contact611 (position 8), the winding of relay 671, battery, and thence to ground. Relay 671 attractsits armatures, thereby opening the energizing circuit for the motor magnet of sequence switch. 610.

'Atthe same time a circuit is establishedbetween ground, battery, the winding of relay 677, to the common conductor 678, alternatecontact and armature of relay671, the common conductor 679 and thence in one direction through thewindingof relay 680 to ground, and in the other direction through the left-hand armatures ofrelays 672 to 676 and thence to ground. 7

It ill be noted that relay 677 isenergized in this circuit, but. that relay 680 wi be short-circuited' until each of the lefth5rd armatures of relays 671 to 676 inclusive has been attracted. i i

The setting of the thousands register, the hundreds register, thetens register, the units register and the stations register is similar to that described in connection with the setting oi the oflice register,and these settings take place simultaneously. VVhen all are completed theregisters will be in the following positions: the office register. in position 8; thethousands register in position 6; the hundreds register in position 9 the tens register in position 7; the units register in position3j and the stations register in position3. y

At .this time also the shunt around the windingof relay 680 willfbe removed and current flowing therethrough will cause its energizatlon.

Thereby a circuit will 7 v be established from ground, the contactand armature of relay 680, the sequence switch contact 50 1 (position 3), to the motor magnet of sequence switch 500, battery and thence to ground. Sequence switch 500 moves its contactors,under control of the contact A intothe fourthposition.

. When the fourth position is reached, a circuit will be established between ground, se-

quence switch contact505 (position 1), to

the common conductor681 to which are multipledthe releasemagnets 6,82to 687 inclusive, and from there. on to battery and thence to ground in each case. The energization of these release magnets causes the release of the keys K to K inclusive, thereby into the fifth position. In this position a circuit known as a fundamental circuit, is established, and extends at this time from ground, sequence switch contact 103 (positions 2to 3) terminal t brush 5, sequence switch contact 506 (position 5), the left-hand armature and contact of counting relay 0 stepping relay SR, brush 5, terminal 25*, sequence switch contact 104: (position 2), the winding of relay 151 to battery and thence to ground.

Relay 151 attracts its armatures, and in so doing, establishes a circuit from ground, left-hand armature and alternate contact of relay 151, sequence switch contact-105 (position 2) the winding of motor magnet of se quence switch 100 to battery and thence to ground. The sequence switch 100, under control of its contact A moves its contactors into the third position, whereupon an alternate circuit for relay 151 is maintained over its contact and right-hand armature, sequence switch contact 104; (positions 2 to 3), and whereby the fundamental circuit is extended through sequence switch contact 10 1 (position 3), to the commutator segment 155.

In position 3 of sequence switch 100, a circuit is established between the ground, left-hand armature and alternate contact of relay 151, sequence switch contact 106 (position 3), the magnet 152 to battery and thence to ground. Magnet 152 attracts its. armature and, in so doing, presses the driving ribbon DB against the constantly rotating roller 153, whereby the brush carriage B is elevated. As the brush 15ipasses over the first conducting segment of commutator 155, the stepping relay SR is intermittently deenergized and energized.

Upon the initial energization of relay SE,

a circuitis established between ground, the

battery and thence to ground. Relay 8 however, is shunted through the conductor 558 over the circuit previously traced, and does not energize until relay SR retracts its armature;

When the brush 154 passes over the first segment of commutator 155, relay SR, through the shunt thus established, is deenergiz'ed, and thereupon retracts its armature. This results in the energization of relay 8 which thereupon transfers the ground, entering the bank of counting relays over conductor 553, through the armature and alternate contact of relay 8 to the armature and normal contact of relay 7 to the winding of relay 7, to battery and thence to ground. Relay 7 is now energized over the circuit leading from ground, the sequence switch contact 507 (position 5), the armature and contact of relay 7, the winding of relay 7 to battery, and thence to ground. In a similar manner each one of the upper counting relays 7 to 0 is energized by the passing of brush 154 over the segments of comn'iutator 155, and the consequent dcnergization of relay SR. \Vhen at lastcounting relay 0 is energized, by attracting its left armature, it opens the fundamental circuit, and removes the ground at sequence switch contact 103 (positions 2 to 3) from the circuit leading to the relay 151 which is therebydeenergized.

The energization of upper counting relay 0 also results in the establishment of a circuit from ground, the right-hand armature and contact of upper counting relay 0, sequence switch contact 508 (position 5), the motor magnet of sequence switch 500 to battery and thence to ground. Sequence switch 500, under control of its contact A moves its contactors into the seventh position, whereupon the circuit for energizing the series of counting relays is broken at the sequence switch contact 507 (position 5).

The deenergization of relay 151 results in the establishment of a circuit from ground, left-hand armature and normal contact of relay 151, sequence switch contact 105 (position 3), motor magnet of sequence switch 100, battery and thence to ground; Sequence switch 100, under control of its contact A moves from the third into the fifth position.

As relay 151 retracts its armatures, the energizing circuit for the magnet 152 is opened, whereupon the brushes secured to the brush carriage B come to rest before "the selected group of trunks.

As position 4 of sequence switch 100 is reached, a circuit is established from ground, sequence switch contact 107 (position 4), and sequence switch contact 107 (positions 4 to 5), sequence switch contact 104 (positions 4 to ,5), winding of relay 151 to battery and thence to ground. Relay 151 is energized in this circuit and is held in an energized condition, as sequence switch 100 reaches the fifth position, through a circuit leading from the grounded terminal 6 of busy trunks of the group to which the brush carriage B has been directed, through brush 7), sequence switch contact 107 (positions 4 to 5) and thence through the circuit previously traced.

In position 5a circuit is established from ground, the left-hand armature and alternate contact of relay 151, the sequence switch contact 106 (position 5), the winding of magnet 152 to battery and thence to ground. Magnet 152 attracts its armature and causes the elevation of the brush carriage B This elevation continues until the brush 5 encounters the terminal t of an idle trunk, whereupon the holding circuit for relay 151 is broken and the consequent deenergization of this relay causes the opening of the energizing circuit for magnet 152 at the alternate contact and left-hand armature of relay 151. The brushes 5, b and 7), therefore, come to rest on the terminals 25, I and 25 of an idle trunk. I

At thesame time a circuit is established between ground, left-hand armature and normal contact of relay 151, sequence switch contact 105 (position 5), the winding of motor magnet of sequence switch 100 to battery and thence to ground. Sequence switch 100'1noves its contactors under the control of contact A into the eleventh position.

As the sixth position is reached, a circuit is established between ground, sequence switch contact 107 (positions 6 to 16), the brush 5 and the terminal t, marking the selected trunk as busy.

When at last position 11 of sequence switch 100 is reached, the fundamental circuit is extended to the connecting circuit at the distant exchange, and may now be traced from ground, the sequence switch contact 201 (positions 1 to 4),,terminal t brush 5, sequence switch contact 109 (position 11), terminal t brush sequence switch contact 506 (position 7 oontact and left-hand armature of the npper counting relay 0 winding of stepping relay SR,brush b terminal t sequence switch contact 110 (position 11), brush N, terminal t sequence switch contact 202 (position 1), winding of relay 250 to battery and thence to ground.

Relay 250 is energized in this circuit and attracts its armatures, establishing thereby analternate circuit for itself extending through the circuit traced as far as sequence switch contact 202 (position 1), at which point it branches and extends through sequence switch contact 202 (positions 1 to 4), left-hand armature and contact of relay 250 to battery and thence to ground.

The attraction of its armatures by relay 250 establishes a circuit from ground, righthancl armature and alternate contact of relay 250, sequence switch contact 203 (position 1), the Winding of motor magnet ofsequence switch 200 to battery and thence to ground. b equence switch 200 moves itscontactors under control 01 its contact A into the second position. y

In position 2 a circuit is established between ground, the right-hand armature and alternate contact of relay 250, the sequence switch contact 20% (position 2), vwinding of magnet 251 to battery and thence to ground. Magnet 251 attracts its armature and presses the driving: ribbon :DR against the constantly rotating roller 252, whereupon thebrush carriage B is elevated. During such elevation, a circuit is established between ground, brush 253, the segments of commutator segment 254, sequence switch contact 202 (position 2), the left-hand. ar mature and contact 'of relay 250,- to battery and thence to ground. The resistance of the path between the sequence-switch 202yand the ground at brush 253 is practically zero,

7 while that leading from sequence switch 202,

back over the fundamental circuit .and through the stepping relay; SR is a definite and much higher quantity. The current through the latter part 50f this .circuit is therefore reduced to such a point that step ping relay SR retracts itsarmature. This occurs each time that brush253 passes over a segment of the commutator254.

- Upon the first attraction of its armature by the relay SE, a circuit is established from ground, sequence switch contact 516 (position 7), the sequence si itch contact 661 (position 3) sequence switch contact 621 (position 6), common conductor armature and normal contact of upper counting relay winding of lower counting r y to battery and'thence to ground. Lower count.- ing relay 3 attracts its armature, and establishes circuit between ground, sequence switch contact 507 (position 7), armature l contact of relay 3, winding of relay 3, ding of relay 3, to battery and thence to ground. Relay 3, however, is shunted through the ground entering the bank of counting relays over common conductor 55%, and does not attract its armature until the relay SR is deenergized for the first time. Whemin response to the brush 258 passing o -Fer the first conducting se ment of commutator 25%, this occurs, then upper counting relay 3 attracts its'armatureand transfers the. ground entering thebank of counting relays over common conductor 55%, through its armature and alternate contact tothe armature and-normal contact of :relay 2. thence throughthe winding of-relay 2 to battery and to ground. In the well-known manner, then, each counting relay in'turn is energized until at last relay 0 attracts its armature,whereupon the. fundamental circuit is broken at .the leiitI-hand armature and contact of relay 0.

A circuitis also established at this time between ground, armature and contact of upper counting relay 0, sequence switch contact 508 (position 7), the winding of the motor magnetof sequence switch 500 to battery and thence to ground. Sequence switch 500 moves its contactorsunder control of its contact A into the ninth position.

The fundamental circuit being opened at the left-hand armature and contact of relay 0, andthe brush 253 resting on an insulated segment of commutator 254:, the relay 250 is deenergized. and retracts its armatures. The energizing circuit for magnet 251 is thereupon opened at the right-hand armature and alternatecontact of relay250, and at thcsame time a circuitis established between ground, the right-hand armature and normal contact of relay 250, sequence switch contact 203 (position 2), the winding of the motor magnet of sequence switch 00 to battery and thence to ground. i

Sequence switch 200, under controlof its contact- A. ,.moves=its contactors into; the third position, thus reestablishing the continuity of the fundamental circuit at the sequence switch contact202 (position 3). The consequent energization of relay 250 and the attraction of its armatures establishes a circuit between ground, the righthand armatureand alternate contact of relay 250, sequence switch contact 203 (position 3), the winding of motor magnet of sequence switch 200 to battery and thenceto ground. Sequence switch 200 moves its contactors, underthe control of its contact A into the fourth position. y TWhenthe sequence switch 500' moves its contactors from the seventh to the ninth position, the counting relays are restored to their original condition. Now, upon the energization of relay SR, a circuit is established 'from ground, the armature and contact of relay SR, sequence switch contact 516, (position 9), sequence switch contact 622 (position 6), sequence switch contact 681 (position. 9), common conductor 555. the

armature and normal contact of upper count ing relay 1, winding of lower counting relay 1, to battery and thence to ground. Lower counting relay 1 attractsits armature and establishes a circuit from ground, scquence switch contact 507 (position 9), the armature and contact of lower counting relay 1, the windingoit' upper counting relay 1, winding of lower counting relay 1 to battery and thence to ground. At this time, however, upper counting relay 1 is shunted in a manner heretofore described, through thezground at the-armature and contact of relay SR.

In position 4 of the sequence switch 200, acircuit is established from ground, right hand armatr e and alternate contact of relay 250, sequence switch contact 204 (position 4), the Winding of magnet 251 to bat tery and thence to ground. The energization of relay 251 again forces the driving ribbon DB against the constantly rotating roller 252 and the brush carriage B is again elevated. Y In position 3 a circuit had been established which is maintained in position 4, from ground, sequence switch contact 205 (positions 3 to 4), the trip magnet TM to battery and thence to ground. The be ginning of the present elevation of the brush carriage B causes an encounter between the finger F and the brush tripping mechanism of the selected brushes in a manner substantially similar to that disclosed in the patent heretofore cited. Now, as the elevation of the brushes continues, contact is made first between ground, brush 255, commutator segment 256, but extends no farther, due to the open circuit at sequence switch contact 206 (position 2). The further elevation of the brushes results in a circuit being established between ground, brush 255, the first segment of commutator 257, the sequence switch contact 202 (position 4:), sequence switch contact 202 (positions 1 to 4:), the winding of relay 250 to battery and thence to ground. This results in the shunting of relay SR, as heretofore described, whereupon relay SR retracts its armature and by thus removing the shunt from around upper counting relay 1, causes the energization of upper counting relay 0". As brush 255 passes off a conducting segment of commutator 257 and on. to an insulated segment of commutator 257, relay SR'is again energized and in attracting its armature establishes a circuit from ground, sequence switch contact 506 (position 9), sequence switch contact 622 (position 6 sequence switch contact 631 (position 9), common conductor 555, the armature an alternate contact of upper counting relay 1, winding of relay 0 to battery and thence to ground. Lower counting relay 0 attracts its armature and establishes a circuit between ground, sequence switch contact 507 (position 9), the armature and contact of lower counting relay 0, winding of upper counting relay o, the winding of lower counting relay 0 to battery and thence to ground. Upon the next encounter between brush 255 and the conducting segment of the commutator 257, stepping relay SR- is deenergized, and in retracting its armatures, removes the shunt from around upper counting relay 0, which therefore attracts its armatures and opens at its left-hand armature the fundamental circuit and closes at its right-hand armature the circuit which extends from ground, right-hand armature and contact of upper counting relay 0, sequence switch contact 508 (position 9),

the winding of motor magnetof sequence switch 500 to battery and thence to ground.

Sequence switch 500, under control of its contact A moves its contactors into the eleventh position, whereupon the energized counting relays are deenergized through the opening of the circuit at sequence switch contact 507 (position 9).

The opening of the fundamental circuit at the left-hand armature of the upper counting relay 0 and the movement of the brush. 255 to aninsulated segment of commutator 257, results in the deenergization of relay 250 which, upon retracting its armatures opens the energizing circuit for the magnet 251, allowing the brushes Z), 6 and I) to come to rest before a selected group of trunks. The retractionof its armatures by relay 250 also results in the establishing a circuit from ground, a right hand armature and normal contact of relay 250, sequence switch contact 203 (position 4), the winding of the motor magnet of sequence switch 200 to battery and thence to ground. Sequence switch 200, under oontrol of its contact A moves its contactors into thefifth position.

In position 5 a circuit is established from ground, sequence switch contact 207 (position 5), sequence switch contact 207 (positions 5 to 6), sequence switch contacts 208 (positions 5 to 6), the winding of relay 250 to battery and thence to ground. Relay 250 is energized in this circuit, and, by attracting its armature, establishes a circuit from ground, right-hand armature and alternate contact of relay 250, sequence switch contact 203 (position 5) ,the winding of motor magnet of sequence switch 200 to battery and thence to ground. Sequence switch 200, under control of its contact A moves its contactors into the sixth position.

In this position the relay 250 is maintained in an energized condition through the contact made between brush 6 and terminal t of a busy trunk. In this position also a circuit is established from ground, the right-hand armature and alter nate contact of relay 250,sequence switch contact 204 (position 6), the winding of magnet 251 to battery and thence to ground. Magnet 251 attracts its armature and thereby causes. the elevation for a third time'of the brush carriage B V The brushes 5", 6 and I) now move over and make contact with the terminals 25, t and t. When an idle trunk is encountered, the energizing circuit for relay 250 is opened at the terminal t whereupon relay 250 retracts its armatures, and, by so doing, opens the energizing circuit of relay 251, which in turn allows the brushes Z), 5 and I) to come to rest upon terminals of the selected idle trunk. Relay 250, in retracting its armatures, also establishes a circuit from ground, the right-hand armature and nor mal contact of relay 250, the sequence switch contact 203 (position 6), the winding of motor magnet of sequence switch 200 to battery and thence to ground. Sequence switch 200, under control of its contact A moves its contactors into the seventh position.

In position 7 a circuit is established from ground, sequence switch contact 207 (positions 7 to 17 brush 6", terminal 23, thus marking the selected trunk as busy.

In this position also the fundamental circuit is reestablished, over which relay 250 is again energized. This results in the establishment of a circuit from ground, right hand armature and alternate contact of re lay 250, sequence switch contact 203 (position 7), winding of the motor magnet of sequence switch 200 to battery and thence to ground. Sequence switch 200, under control of its contact A moves itsrcontactors into the eighth position.

In position 8 a circuit is established from ground, right-hand armature and alternate contact of relay 250, sequence switch contact 204 (position 8), the brush 6, the terminal 2?, sequence switch contact 301 (position 1), the winding of relay 351 to battery and thence to ground. Relay 351 attracts its armatures and in turn establishes a circuit from ground, the left-hand armature and alternate contact of relay 351, sequence switch contact 302 (position 1), winding of relay 352 to battery and thence to ground. Relay 352 attracts its armatures, and in its turn establishes a circuit from ground, the lower armature and alternate contact of relay 352, sequence switch contact 303 (position 1), to the motor magnet of sequence switch 300 to battery and thence to ground. Sequence switch 300 under control of its contact A moves its contactors into the second position.

It should be noted at this point that upon the energization of relay 352 an alternate circuit for this relay is established from ground, battery, winding ofrelay 352, alternate contact and upper armature of relay 352, terminal 6', brush 5, sequence switch contact 207, (positions 7 to 17) and thence to ground,

The reestablishment of the fundamental circuit results in the extending of a circuit from ground, the armature and contact of relay SR, the sequence switch contact 509 (position 11), sequence switch contact 662 (position 3), sequence switch contact 632 (position 9), common conductor 556, armature and normal contact of upper counting relay 9, winding of lower counting relay 9 to battery andthence to ground. Lower counting relay 9 attracts its armature and establishes a circuit from ground, sequence switch contact 507 (position 11 armature and contact of relay 9, winding of upper counting relay 9, winding of lower counting relay 9 to battery and thence to ground, in a manner similar to that heretofore described. Relay 9 does not energize at this time, due to the shunt extending back over the common conductor 556 to ground at the armature of the stepping relay SE.

The movement or" the contactors of sequence switch 300 into position 2, establishes a circuit from ground, battery, magnet 353, sequence switch contact 302 (position 2), alternate contact and left-hand armature of relay 351 to ground. ii lagnet 353 presses the driving ribbon DR against the constantly rotating roller 351, which elevates the brush carriage B at a high speed. As the brush carriage B is elevated, the brush 355 establishes a connectienbetween ground, the brush the first conducting segment of commutator 356, the se quence switch contact 304 (position 2), the terminal t the brush b the sequence switch contact 209 (position 8), the sequence switch contact 202 (positions 7 to 12), left hand armature and contact of relay 250 to battery and thence to ground. The circuit just described shunts out the w' iding of re lay SR 111 a manner heretofore described,

and the relay SR, in retracting its armature,

removes the shunt from around the upper counting relay 9, which results in the encr- V gization of this relay. As the brush 355 conbank of counting relays over the common conductor 556 is extended through the armature and alternate contact of upper counting relay 9, the armature and normal contact of upper counting relay 8, to the winding of lower counting relay 8, to battery and thence to ground. Lower counting re lay 8 is energized and completes a circuit from ground, sequence switch contact 507, armature and contact of relay 8, the winding of upper counting relay 8, the winding of lower counting relay 8 to battery and thence to ground.

As brush 355 continues in. its upward movement, the counting relays in turn are energized, until at last the energization ofthe upper ccunting relayo results in the opening of the fundamental circuit and the move ment of the sequence switch 500 into position 13.

Since the impulses for the selection of the brushes at the connector switch are greater in this case than five, the commutator seg- .ment 359 is encountered by the brush 357 at thistime and a circuit is thereby established which extends from ground, brush 357, commutator segment 359, sequence switch contact 306 (position 2), winding of relay 360, battery and thence to ground. Relay 360 attracts its armatures and com pletes a locking circuit for itself which extends from ground, the right-hand armature and both contacts of relay 360, sequence switch contact 306 (positions 2 to 13) winding of relay 360, battery and thence to ground.

The opening of the fundamental circuit results in the deenergization of relay 250, which, upon retracting its armatures, completes a circuit from ground, the. right-hand armature and normal contact of relay 250, sequence switch contact 203 (position 8), the winding of motor magnet of sequence switch 200 to battery and thence to ground. Sequence switch 200, under control of its contact A moves its contactors into the ninth position. At the same time the removal of the ground from the alternate contact of relay 250 results in the deenergization of relay 351, which in turn results in the deenergization of the up-drive magnet 353.

. The deenergization of relay 351 also results in the establishment of a circuit from ground, the armature and normal contact of relay 351, sequence switch contact 303 (position 2), the winding of motor magnet of sequence switch 300 to battery and thence to ground. Sequence switch 300, under. control of its contact A moves its contactors into the third position.

As sequence switch 300 reaches position 3, a circuit is established from ground, sequence switch contact 305 (positions 3 to 4:), trip magnet TM, to battery and thence to ground. Trip magnet TM attracts its armature and brings the. fingers F 3 and F in the path of the tripping mechanism of the brush carriage B As sequence switch 200 reaches the ninth position, the fundamental circuit is restablished, and the consequent energization of the relay 250 drives the sequence switch 200 into its tenth position in the manner heretofore described, whereupon the circuit for the energization of relay 351 is established through sequence switch contact 301'(position 3). The consequent energization of relay 351 results in the attraction of its armatures, and the establishment of a circuit from ground, the left-hand armature and alternate contact of relay 351, sequence switch contact 303 (position 3), the winding of motor magnet of sequence switch 300 to battery and thence to ground. Sequence switch 300 moves its contactors, under the control of contact A, into the fourth position, in which a circuit is established from ground, the left-hand armature and alternate.

contact of relay 351, sequence switch contact 302 (position 4;), the winding of up-drive magnet 353 to battery and thence to ground. Magnet 353 attracts its armature and presses the driving ribbon DR against the constantly rotating roller 35 i, whereby brush carriage 13 is elevated again at a high speed. Upon its first movement inthis direction, the finger F comes in contact with the brush tripping mechanism of the selected brushes, in a. manner similar to that heretofore described,

It should be noted here that both fingers F and F are arranged to trip the same set of brushes, and that the selection of one or the other for this service depends on whether or not the regular number of brush tripping impulses have been transmitted.

In this case, an additional five impulses have been sent, and the brush carriage has, therefore, beendriven into the second brush tripping 'zone.

Nhen, upon the movement of the sequence witch 200 into position 9, the fundamental circuit was again reestablished, the stepping relay SR was energized. A circuit was thereupon extended from ground, the armature and contact of stepping relay SR, the sequence switch contact 509 (position 13), the sequence switch contact 641 (position 7), the commonconductor 557, the armature and normal contact of upper counting relay 7, the winding of lower counting re.- lay 7 to battery and thence to ground. Lower counting relay 7 attracts its armature and establishes a circuit from ground, sequence switch contact 507 (position 13), the armature and contact of lower counting relay 7, the winding of upper counting relay 7, the winding of lower counting relay 7 to battery, and thence to ground. Upper counting relay 7, however, is shunted at this time through ground at the contact and armature or the relay SR, and stays energized until the relay SR has been deenergized.

As the brush carriage B is, therefore,

further elevated, a circuit is established be-- tween brush 357, the first conducting segment of the commutator 358, the sequence switch contact 304 (position 4), the terminal t the brush b thesequence switch contact 209 (position 10), the sequence counting relay 0. This results again in the deenergization of relay 250, and the consequent deenergization of relay 351.

At thesame time a circuit is established between ground, the right-hand armature and contact of upper counting relay of 0,

the sequence switch contact 508 (position 13), to the motor magnet of sequence switch 500, battery, and thence to ground. Sequence switch 500, under control of its contact A moves its contactors into the fifteenth position.

The denergization of relay 250 results in the establishment of a circuit between ground, the right-hand armature and normal contact of relay 250, sequence switch contact 203 (position 10), winding of motor magnet of sequence switch 200 to battery and thence to ground. Sequence switch 200, under. control of its contact A moves its contactors into the eleventh position.

The deenergization of relay 351 results in the opening of the energizing circuit for magnet 353 and the establishment of a circuit from ground, the left-hand armature and normal contact of relay 351, sequence switch contact 303, (position 4:), the winding of motor magnet of sequence switch 300 to battery and thence to ground. Sequence switch 300, under control of its contact A, moves its contactors into the fifth position.

The movement of the sequence switch 200 into position 12 is accomplished by the reestablishment of the fundamental circuit through the sequence switch contact 202 (position 11), and the consequent energization of relay 250. Relay 250, in attracting its armatures, establishes a circuit from ground, the right-hand armature and alternate contact of relay 250, sequence switch contact 203 (position 11), winding of motor magnet of sequence switch 200 to battery, and thence to ground. Sequence switch 200 under control of its contact A moves its contactors into the twelfth position.

In position 12, a circuit is established from ground, right-hand armature and alternate contact of relay 250, sequence switch contact 204: (position 12), brush 6, terminal t sequence switch contact 301 (position 5), winding of relay 351 to battery, and thence to ground. Relay 351 attract-s its armatures, and thereby establishes a locking circuit for itself, extending through the circuit traced up to th sequence switch contact 301 (position 5) where it branches and extends through sequence switch contacts 301 (positions 1 to 6), the right-hand armature and contact of relay 351 to battery, and thence to ground.

The energization of relay 351 also results in the establishment of a circuit from ground. left-hand armature and alternate contact of relay 351, sequence switch contact 303 (position 5), and winding of motor magnet of sequence switch 300 to battery, and thence to ground. Sequence switch 300, under control of its contact A moves its cont-actors into position 6.

In position 6 a circuit is established from ground, the left-hand armature and alternate contact of relay 351, the sequence switch contact 302 (position 6), the winding of magnet 361 to battery, and thence to ground. Magnet 361 attracts its armature and presses the driving ribbon DB against the constantly rotating roller 362 which thereby, elevates the brush carriage B at a low speed.

Upon the last energization of the stepping relay SR which took place when sequence switch 200 moved its 'contactors into the eleventh position, a circuit is established from ground, the armature and contact of relay SR, the sequence switch contact 50:) (position 15), the sequence switch contact 651 (position 5), the common conductor 558, through the armature and normal contact of upper counting relay 5, and the winding of lower counting relay 5 to battery, and thence to ground. In the elevation of the brush carriage B, the brush 355 intermittently makes contact with the conducting segments of the commutator 356, whereby a circuit is extended from ground, the brush the commutator 356, the'sequence switch contact 30% (position 6), the terminal 25 the brush 5 the sequence switch contact 209 (position 12), and thence through the fundamental circuit, and the winding of relay 250 in a manner similar to that previously described. The stepping relay SR is intermittently shunted and caused to retract its armatures, whereby the counting relays are successively energized until upper counting relay 0 is reached, at which time the fundamental circuit is Opened.

The opening of the fundamental circuit by the energization of upper counting relay 0 results in the movement of the sequence switch 500 into position 16, and also results in the de'nergization of relay 250.

As sequence switch 500 reaches position 16, a circuit is established between ground, the sequence switch contact 510 (position 1.6), brush Z)", terminal sequence switch contact 105 (position 11), to the winding of motor magnet of sequence switch 100 to battery, and thence to ground.

Sequence switch 100, under control of its contact A moves its contactors intothe sixteenth position, whereupon the talking conductors of the selected connecting circuit are extended through the first selector at the sequence switch contacts 109 (positions 12 to 16) and 110 (positions 12 to 16). 1

As sequence switch 100 moves out of po sition 11, a circuit through which relay 551 is held energized, is opened at the sequence switch contact 102 (positions 2 to 11), resulting in the denergization of this relay. A. circuit is thereupon established between ground, the right-hand armature and normal contact of relay 551, the sequence switch contact 501 (positions 3 to 16), the winding of motor magnet of sequence switch 500 to battery, and thence to ground. Sequence switch 500, under control of its contact A moves its contactors into the seventeenth position.

In position 17, a circuit is established between ground, sequence switch contact 511 (position 17), winding of magnet 559, bat tery, and thence to ground. Magnet 559 attracts its armature, and thereby presses the driving ribbon DB against the constantly rotating roller 560, whereby the brush carriage B is caused to return to normal position.

When this normal position has been reached, a circuit is established between ground, the brush 561, the commutator562, the sequence switch contact 508 (position 17), the winding of motor magnet of sequence switch 500 to battery, and thence to ground. Sequence switch 500, under control of the contact A moves its contactors into the first or normal position, at which time it is ready to perform the functions heretofore described in connection with any other cord circuit which the operator may select for the initiation of another call.

The deenergization of relay 250 now re- 2 sults in the establishment of a circuit from ground, the right-hand armature and the normal contact of relay 250, the sequence switch 203 (position 12), the winding of motor magnet of sequence switch 200 to battery, and thence to ground. Sequence switch 200, under control of its contact A moves its contactors into the sixteenth position, whereupon the talking circuit eX tended from the operators connecting circuit through first selector is now extended to the connecting circuit at the second selector through sequence switch contact 201 (positions 13 to 17) and sequence switch contact 209 (positions 13 to 17).

The deenergization of relay 250 also re sults in the deenergization of relay 351, and, in turn, the de'c'nergization of magnet 361, whereby the elevation of brush carriage B is halted and the brushes I), I2 and b are brought to rest on the terminals 6, 15 and t of the selected subscribers line.

Upon the extension of the operators connecting circuit shown in Fig. 1 to the connecting circuit diagrammatically shown in Fig. 2, a circuit is completed between ground, the upper right-hand winding of repeated coil RC the sequence switch contact 110 (position 16), the brush Z2 the terminal i the sequence switch contact 209 (positions 13 to 17), the upper left-hand winding of repeating coil RC the winding of relay 258 to battery, and thence to ground. Relay 258, therefore, attracts its armature before position 16 has been reached, and thereby prevents the establishment of a circuit to drive the sequence switch 200 into a further position, as will be described hereafter. I

The last deenergization of relay 351 resulted, in addition to the opening of the circuit for magnet 361, in the establishment of a circuit from ground, the lefthand armature and normal contact of relay 351, the sequence switch contact 303 (position 6), the winding 01" the motor magnet of sequence switch 300, to battery and thence to ground. Sequence switch 300, under control of its contact A moves its co-ntactors into the thirteenth position. In position 13, however, a circuit is extended from ground, the right-hand armature and first contact of relay 360, the sequence switch contact 307 (position 13), through the winding of motor magnet 300 to battery, and thence to ground. Sequence switch 300, therefore, moves its contactors, under the control of its contact A into the fourteenth position, in which relay 360 is deenergized.

)Vhen position 10 of sequence switch 300 is reached, a circuit is established from ground, sequence switch contact 308 (positions 10 to 16), to the brush Z), the terminal t of the selected line, whereupon this line is marked as busy.

As sequence switch 200 reaches position 16, a circuit is established from ground, the sequence switch contact 212 (position 16), the contact and armature of relay 259, contact and armature of relay 260, the winding of relay 261 to battery, and thence to ground. Relay 261 is energized in this circuit and attracts its armature;

It should be noted at thispoint that the signaling system described herein is the well known Thompson and Rodes party line system, described in U. S. Patent 6%,647 and in Kempster B. Millers American T dephone Practice, pages 439 to 4:41. It should be further noted that a particular method of ringing subscribers bells is not an essential part of the invention and that other systems than that shown might be employed without departing from the spirit of the invention.

The called subscribers bell is now rung through current flowing over the circuit extending from a source of plus pulsating current, the left-hand armature and normal contact of relay 262, the winding of relay 259, the lower armature and alternate contact of relay 261, sequence switch contact 210, the brush 6 the terminal t the left-hand armature and contact of relay 360, the sequence switch contact 309 (position 14), the brush 6, the terminal t, over the upper limb of the subscribers line, in parallel through each one of the condensers at the substations S S S and S the winding of the relays at each one of these stations, thence through the secondary of the induction coils at each one of these stations, and then to the lower limb of the subscribers line, the terminal 5 the brush 5, the sequence switch contact 310 (position 14), the terminal t the brush 6 sequence switch contact 211 (positions 14 to 16), the alternate contact and upper armature of relay 261 to ground. The four relays at the subscribers substations will be energized in this circuit and will attract their .armatures, whereupon the ringing current flowing out over the upper limb of the subscribers line will find a parallel path extending through the condensers, armatures, contacts of the substation relays, and bells of the substations S and S to ground. This current will not flow through the bells of the stations S and S since the lower limb on the subscribers line extends to a ground at the upper armature and alternate contact of relay 261, which ground acts as a shunt around these bells.

It should be noted that the bells at substations S and S are'arranged to respond to currents of different characters, that at the substation S responding to minus pulsating current, and that at the substation S responding to plus pulsating current. The current being supplied to these lines is of plus pulsating current, hence, of the four bells shown, only that at the station S will respond.

Now the plus pulsating current flowing out over the circuits described to actuate the four relays at the four subscribers substations and the bell at substation S is not sufliciently large to cause the energization of relay 259. When, however, the subscriber at substation S in response to the summons of his bell, removes the receiver from its switchhook, a path of low resistance is bridged across the telephone line, and the increase in flow of plus pulsating current is suflicient to cause the energization of relay 259. Thereupon, the circuit heretofore described for the energization of relay 261 is opened at the armature and contact of relay 259, and may now be traced from ground, the sequence switch contact 212 (position. 16), the winding of relay 260, the winding of relay 261 to battery, and thence to ground. Relay 260 attracts its armature and completes a locking circuit for itself from ground, battery, the alternate contact and armature of relay 260 through the winding of relay 260, sequence switch contact 212 .(position 16), to ground.

Relay 261 is shunted in this circuit and retracts its armatures, whereupon the ringing current is disconnected from the subscribers line, and a talking circuit is established, extending from the repeating coil RC to the substation S. This circuit may be traced from ground, the upper right-handwinding of repeating coil RC the normal contacts of the upper armature of relay 261, the sequence switch'contact 211 (position 16), the brush 6 the terminal t the sequence switch contact 310 (position 14), the brush 6 the terminal to the lower limb of the telephone line, thence through the apparatus of the substation S the upper limb of the telephone line, to the terminal the brush 6 the sequence switch contact 309 (position 14), the contact and armature of relay 360, the terminal 25 the brush Z9 se quence switch contact 210 (position 16), the lower armature and contact of relay 261, the winding of supervisory relay 263 to the lower right-hand winding of repeating coil RC to battery, and thence to ground.

Current flowing over thi circuit energizes the supervisory relay 263, and a circuit is thereby established from ground, the

armature and contact of relay 263, the impedance coil 26%, the lower left-hand winding of repeating coil RC the sequence switch contact 201 (positions 13 to 17), terminal t, brush 7), sequence switch contact 109 (positions 12 to 16), supervisory relay 156, the lower right-hand winding of repeating coil RC to battery, and thence to ground. Supervisory relay 156 thereupon signals the operator in the well-known manner that the called subscriber has answered his telephone.

When the conversation over this circuit has been completed, the subscriber at substation S in replacing his receiver on its hook, de'e'nergizes supervisory relay 263, which, in turn, deiinergizes supervisory relay 156.

The subscriber at substation S in replacing his receiver on its hook in a, well-known manner de't nergizes the supervisory relay 157. The resulting signals are displayed before the operator and are recognized by her as a signal to disconnect. She thereupon removes the plug P from the jack J, which results in the deiinergization of relay 150. Relay 150 upon retracting its armature establishes a circuit from ground, the'righthand armature and normal. contact of relay 150, the sequence switch contact 101 (positions 2 to 17), the winding of motor magnet of sequence switch to battery, and thence to ground. Sequence switch 100, under control of its contact A moves its contractors to the eighteenth position.

In position 18 a circuit is established from ground to sequence switch contact 103 (position 18), the winding of magnet 158, battery, and thence to ground. Magnet 158 at tracts its armature and presses the driving ribbon DB against the constantly rotating roller 159, whereby the brush carriage B is caused to return to a normal position. .Vheu this position has been reached, a circuit is established from ground, brush 154C, commutator segn'ient 160, sequence switch contact 105 position 18), the Winding of motor magnet 100, to battery, and thence to ground. Sequence switch 100, under control of its contact r moves its contactors into the first or normal posit-ion, whereupon the first selector is fully restored.

As the sequence switch 100 passes out of position 16, a circuit heretofore described for the energization of relay 258 is opened at the sequence switch contact 110. The consequent deenergization of relay 258 establishes a circuit for ground, armature and contact of relay 258, the sequence switch contact 203 (position 16), the winding of motor magnet of sequence switch 200 tobat tery, and thence to ground. Sequence switch 200, under control of its contact A moves its contactors into the eighteenth position.

In position 18 of the sequence switch 200, a circuit is established from ground, sequence switch 205 (position 18),the winding of magnet 265 to battery and thence to groui'id. Magnet 265 attracts its armature and presses the driving ribbon DR against the constantly rotating roller 260, whereupon the brush carriage B is caused to return to normal position. When this position is reached, a circuit is established from ground, brush 255, commutator segment 267, sequence switch contact 203 (position 18), through the winding of motor magnet of sequence switch 200 to battery, and thence to ground. Sequence switch 200. under control of its contact A moves into the first or normal position, whereupon the second selector is fully restored.

Vvhen sequence switch 200 moves out of position 17, the circuit for maintaining relay 352 energized was broken at the sequence switch contact 207. Relay 352, upon retracting its armatures, establishes a circuit from ground, the lower armature and normal contact of relay 352, the sequence switch contact 307 (positions 2 to 17), the winding of motor magnet of sequence switch 300 to battery, and thence to ground. Sequence switch 300, under control of its contact A moves into the eighteenth position.

In position 18 a circuit is established from ground, the sequence switch contact 305 (position 18), the winding of magnet 363 to battery, and thence to ground. Magnet 363 attracts its armature and presses the driving normal position is reached, a circuit is established between ground, brush '357, the commutator segment 365, the sequence switch contact 307 (position 18), the winding of motor magnet of sequence switch 300 to battery, and thence to ground. Sequence switch 300, under control of its contact A moves into the first or normal position, whereupon this connector switch is fully restored.

Referring now especially to Fig. 3, it should be noted that while the sequence switch 300 was in position 2 that ten brush selecting impulses were sent. Now there are five sets of brushes on such a. switch which are so arranged here that each may be selected through the transmission of two sets of impulses one consisting of five or less and the otherconsisting of five plus five or less. For instance the first set of brushes may be selected through either one or six impulses and the fifth set may be selected through either five or ten impulses. In this case ten impulses were set whereby the fifth set of brushes was selected in the second of the two ways possible. The choice of the .second way resulted in the energization of relay 360 which prevented the sequence switch from resting in position 13 and thereby re sulted in a reversal of the line conductors at sequence switch contacts 309 and 310. It should be noted that the energiZat-ion of relay 360 was not accomplished until the brush 355 had passed over five of the conducting segments of commutator 356, this being a measure of the distance between the commutator 359 and the normal position of the brush 357.

If the sequence switch 660 hadbeen set in position 1 instead of position 3, then the brush selecting impulses would have been determined by a circuit, part of which may be traced from sequence switch contact 662 (position 1), sequence switch contact 633 (position 9), common conductor 563 to the armature and normal contact of upper counting relay 4 and so forth, whereby five instead of ten impulses would have been sent. In such-a case the relay 360 would not have been energized and the sequence switch 300 would have rested in position 13 during the period of conversation.

Similarly five extra impulses might have been sent in selecting the brushes of the selector B This would have caused brush 255 to travel over a commutator segment 256, which would have completed a circuit from ground, brush 255, commutator segment 256, sequence switch contact 206 (posiringing current from plus pulsating to minus pulsating current so that the station S would have been rung instead of the station S It will therefore be seen from the foregoing description that through the provision of a double brush tripping zone and the provision of a double set of brush tripping fingers that a selection of ringing current may be made at one selector switch and a reversal oi the talking conductors made at a subsequent connector switch, whereby any one. of four different parties may be selectively summoned.

What is claimed is:

1. In a telephone system, a telephone line, means including an automatic selective switch for extending a connection to said line, a plurality of series of corr sponding selective positions for said switch, means for causing said device to effect the same con nection in a plurality of coriesponding positions, said means including a plurality of corresponding actuating membe. a source of current, and means responsive to the movement of said selective switch to different corresponding positions for differently applying said current to said line.

2. In a telephone system, a telephone line, means including an electrically operated se lecting device for extending, a connection to said line, twoseries of corresponding selec tive positions for said device, means including a separate actuating member for rendering said device operative in each position, said device being arranged to efi'ect the same line selecting operation when moved to either of its corresponding positions, a source of current, and means dependent on whether said selecting device is positioned in one of its first or second series of positions for differently applying said current to said line.

8. In a telephone system, a calling line, a called line, a pluralityof stations on said called line, a signaling device at each of said stations respectively, diii'erently responsive to ringing current, means including a rectilinearly movable connector switch for establishing a connection from one of said lines to the other, a single terminal set for said called line at said switch, a source of ringing current, means controlled solely by said switch in making connection to said terminal set for joining said source-to one or the other talking conductor terminals of the said line.

4. In a telephonesystem, a calling line, a called line, a plurality of stations on said called line, signaling devices at said stations differently responsive to ringing current, means including a connector switch for establishing a connection from one of said lines to the other, a single terminal set for said called line at said switch, a source of ringing current, and means including a separate actuating member for controlling said switch in each selective position thereof in making connections with said terminal set for joining said source to one or the other talking conductor terminals of said line.

5. In a telephone system, a telephone line, means including an electrically operated switch controlling device for extending a connection to said line, a plurality of series of corresponding selective positions for said device, means including a separate actuating member for rendering said device operative in each position, said device being arranged to effect in corresponding positions the same switching operation, a source of current, and means dependent on to which of its corresponding positions said selecting device has been moved for differently applying said current to said line.

6. In a telephone system, a telephone line, means including a rectilinearly movable selective switch for extending a connection to said line, a plurality of brushes on said switch, a device having a plurality of actuating members corresponding to a plurality of selective positions of said brushes, a source of current, and means dependent on whether said brushes have been operated in one or another of its selective positions for differently associating said source of current with said line.

7. In a telephone system, a telephone line, means including an automatic selective switch for extending a connection to said line, a plurality of sets of brushes on said switch, means for selecting a desired one of said sets of brushes, said means including a plurality of actuating members for selecting the same set of brushes, a source of current, and means dependent on the manner in which said brushes are selected for differently associating said source of current with said line.

8. In a telephone system, a telephone line, means including a rectilinearly movable selective switch for extending a connection to said line, a plurality of sets of brushes on said switch, a brush selecting device, means for moving said sets of brushes into a plurality of corresponding selective positions, a source of current, and means dependent on whether said sets of brushes have been moved to one or another of its corresponding positions for differently as sociating said source of current with said line.

9. In a telephone system, a telephone line, means including a rectilinearly movable switching device for extending a connection to said line, electrically operated means for moving said device into a plurality of sets of corresponding selective positions, said device being arranged to effect the same switching operation when in each of its corresponding positions, a source of current, and means controlled by said device in passing into a selected position for joining one or another pole of said source of current to said line.

10. In a telephone system, a telephone line, means including a mechanically operated switch for extending a connection to said line, selective means at said switch capable of actuating said switch in a plur'ality of corresponding selective positions, said selective means including a separate actuating member for each position, the selection accomplished at corresponding positions-being the same, a source of current, and means dependent on whether said selective switch is actuated in one or another of its selective positions for diii'erently applying said current to said line.

11. In a telephone system, a telephone line, means including a multi-brush switch for extending a connection to said line, a plurality o1 brush selecting positions for said switch, means including a separate actuating member for the selection of brushes in each position, the brushes selected at corresponding positions being the same, a source of current, and means dependent on whether said brushes have been selected in one or another corresponding position for differently applying said current to said line.

12. In a telephone system, a telephone line, means including a 1nult1-brush switch for extending a connection to said line, a

rotatable brush selecting device at said switch, a plurality of selective positions for said switch, said brush selecting devices having a separate member for actuating said brushes in each selective position, the brush selected at corresponding positions of said switch being the same, a source of current, and means dependent on whether said selecting device has selected a set of brushes in one or another position for differently applying said current to said line.

13. In a telephone system, a telephone line, means including a multi-brush connector switch for establishing a connection to said line, a brush selecting device including a plurality of actuating members at said switch, a single terminal set for said line at said switch, controlling means for said brush-selecting device differently operated to cause said brush to be selected by one or another of said actuating members, a source of ringing current, means for moving the selected brush set into engagement with said terminal set, and means dependent on the position in which said brushes have been selected for joining said current to one or the other of the talking conductors of said line.

14-. In a telephone system, a calling line, a called line, two telephone stations on said called line, a signaling device at each of said stations respectively, said signaling de vices being connected one to each of the conductors of said called line, means including a multi-brush rectilinearly movable connector switch for establishing a connection from said calling to said called line, a brush selecting device at said switch including a plurality of actuating members, a single terminals set for said called line at said switch, controlling means for said selecting device differently operated to cause said device to select in a plurality of positions the brush set having access to said terminal set, means for moving said selected brush set to make connection to said terminal set, a source or ringing current, and means dependent on the position in which said brush set has been selected for joining said source of current to one or the other of the conductors of said called line.

15. In a telephone system, a telephone line, two stations on said line, signaling devices at each of said-stations respectively, said signaling devices being connected one to each of the conductors of said line, means including a multi-brush rectilinearly movable switch for establishing a connection to said line, a single terminal set forsaid line at said switch, a brush selecting device at said switch comprising a rotatable shaft and a plurality of brush tripping members, said members being arranged to trip the same set of brushes when said switch is in different positions, controlling means for said brush tripping device for causing it to assumea position to trip the brush set having access to said terminal set, means for moving the selected brush set into engagement with said terminal set, a source of current, and means dependent on whether said brushes have been tripped in one or another position for joining said source to one or the other of the conductors of said line.

16. In a telephone exchange system, a telephone line, two stations on said line, signaling devices at said stations, respectively, said signaling devices being connected one to each of the conductors of said line, means includinga multi-brusn rectilinearly movable switch for establishing connection to said line, a brush tripping device at said switch capable of tripping the same set of brushes in one or more positions thereof, controlling means for said brush tripping device for causing it to selectthe brush having access to said telephone line, a source of current,

and means dependent on the position in which said brush set was tripped for joining one or the other poles of said source to said line. i

17. In a telephone system, a telephone line, two stations on said line, signaling devices at said stations respectively, said signaling devices-being connected one to each 

